<?xml version="1.0" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>EVP_PKEY-X25519</title>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<link rev="made" href="mailto:root@m67js.p1s.plx.sd.apple.com" />
</head>

<body>



<ul id="index">
  <li><a href="#NAME">NAME</a></li>
  <li><a href="#DESCRIPTION">DESCRIPTION</a>
    <ul>
      <li><a href="#Common-X25519-X448-ED25519-and-ED448-parameters">Common X25519, X448, ED25519 and ED448 parameters</a></li>
      <li><a href="#ED25519-and-ED448-parameters">ED25519 and ED448 parameters</a></li>
    </ul>
  </li>
  <li><a href="#CONFORMING-TO">CONFORMING TO</a></li>
  <li><a href="#EXAMPLES">EXAMPLES</a></li>
  <li><a href="#SEE-ALSO">SEE ALSO</a></li>
  <li><a href="#COPYRIGHT">COPYRIGHT</a></li>
</ul>

<h1 id="NAME">NAME</h1>

<p>EVP_PKEY-X25519, EVP_PKEY-X448, EVP_PKEY-ED25519, EVP_PKEY-ED448, EVP_KEYMGMT-X25519, EVP_KEYMGMT-X448, EVP_KEYMGMT-ED25519, EVP_KEYMGMT-ED448 - EVP_PKEY X25519, X448, ED25519 and ED448 keytype and algorithm support</p>

<h1 id="DESCRIPTION">DESCRIPTION</h1>

<p>The <b>X25519</b>, <b>X448</b>, <b>ED25519</b> and <b>ED448</b> keytypes are implemented in OpenSSL&#39;s default and FIPS providers. These implementations support the associated key, containing the public key <i>pub</i> and the private key <i>priv</i>.</p>

<p>No additional parameters can be set during key generation.</p>

<h2 id="Common-X25519-X448-ED25519-and-ED448-parameters">Common X25519, X448, ED25519 and ED448 parameters</h2>

<p>In addition to the common parameters that all keytypes should support (see <a href="../man7/provider-keymgmt.html">&quot;Common parameters&quot; in provider-keymgmt(7)</a>), the implementation of these keytypes support the following.</p>

<dl>

<dt id="group-OSSL_PKEY_PARAM_GROUP_NAME-UTF8-string">&quot;group&quot; (<b>OSSL_PKEY_PARAM_GROUP_NAME</b>) &lt;UTF8 string&gt;</dt>
<dd>

<p>This is only supported by X25519 and X448. The group name must be &quot;x25519&quot; or &quot;x448&quot; respectively for those algorithms. This is only present for consistency with other key exchange algorithms and is typically not needed.</p>

</dd>
<dt id="pub-OSSL_PKEY_PARAM_PUB_KEY-octet-string">&quot;pub&quot; (<b>OSSL_PKEY_PARAM_PUB_KEY</b>) &lt;octet string&gt;</dt>
<dd>

<p>The public key value.</p>

</dd>
<dt id="priv-OSSL_PKEY_PARAM_PRIV_KEY-octet-string">&quot;priv&quot; (<b>OSSL_PKEY_PARAM_PRIV_KEY</b>) &lt;octet string&gt;</dt>
<dd>

<p>The private key value.</p>

</dd>
<dt id="encoded-pub-key-OSSL_PKEY_PARAM_ENCODED_PUBLIC_KEY-octet-string">&quot;encoded-pub-key&quot; (<b>OSSL_PKEY_PARAM_ENCODED_PUBLIC_KEY</b>) &lt;octet string&gt;</dt>
<dd>

<p>Used for getting and setting the encoding of a public key for the <b>X25519</b> and <b>X448</b> key types. Public keys are expected be encoded in a format as defined by RFC7748.</p>

</dd>
</dl>

<h2 id="ED25519-and-ED448-parameters">ED25519 and ED448 parameters</h2>

<dl>

<dt id="mandatory-digest-OSSL_PKEY_PARAM_MANDATORY_DIGEST-UTF8-string">&quot;mandatory-digest&quot; (<b>OSSL_PKEY_PARAM_MANDATORY_DIGEST</b>) &lt;UTF8 string&gt;</dt>
<dd>

<p>The empty string, signifying that no digest may be specified.</p>

</dd>
</dl>

<h1 id="CONFORMING-TO">CONFORMING TO</h1>

<dl>

<dt id="RFC-8032">RFC 8032</dt>
<dd>

</dd>
<dt id="RFC-8410">RFC 8410</dt>
<dd>

</dd>
</dl>

<h1 id="EXAMPLES">EXAMPLES</h1>

<p>An <b>EVP_PKEY</b> context can be obtained by calling:</p>

<pre><code>    EVP_PKEY_CTX *pctx =
        EVP_PKEY_CTX_new_from_name(NULL, &quot;X25519&quot;, NULL);

    EVP_PKEY_CTX *pctx =
        EVP_PKEY_CTX_new_from_name(NULL, &quot;X448&quot;, NULL);

    EVP_PKEY_CTX *pctx =
        EVP_PKEY_CTX_new_from_name(NULL, &quot;ED25519&quot;, NULL);

    EVP_PKEY_CTX *pctx =
        EVP_PKEY_CTX_new_from_name(NULL, &quot;ED448&quot;, NULL);</code></pre>

<p>An <b>X25519</b> key can be generated like this:</p>

<pre><code>    pkey = EVP_PKEY_Q_keygen(NULL, NULL, &quot;X25519&quot;);</code></pre>

<p>An <b>X448</b>, <b>ED25519</b>, or <b>ED448</b> key can be generated likewise.</p>

<h1 id="SEE-ALSO">SEE ALSO</h1>

<p><a href="../man3/EVP_KEYMGMT.html">EVP_KEYMGMT(3)</a>, <a href="../man3/EVP_PKEY.html">EVP_PKEY(3)</a>, <a href="../man7/provider-keymgmt.html">provider-keymgmt(7)</a>, <a href="../man7/EVP_KEYEXCH-X25519.html">EVP_KEYEXCH-X25519(7)</a>, <a href="../man7/EVP_KEYEXCH-X448.html">EVP_KEYEXCH-X448(7)</a>, <a href="../man7/EVP_SIGNATURE-ED25519.html">EVP_SIGNATURE-ED25519(7)</a>, <a href="../man7/EVP_SIGNATURE-ED448.html">EVP_SIGNATURE-ED448(7)</a></p>

<h1 id="COPYRIGHT">COPYRIGHT</h1>

<p>Copyright 2020-2021 The OpenSSL Project Authors. All Rights Reserved.</p>

<p>Licensed under the Apache License 2.0 (the &quot;License&quot;). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <a href="https://www.openssl.org/source/license.html">https://www.openssl.org/source/license.html</a>.</p>


</body>

</html>


